• Haircut Dude is a hit man. He’s a remorseless psychopath. He’s hunting dude 2.
• Dude 2 stumbled across a bunch of money from a drug-deal-gone-wrong. He’s trying to hide from everyone who wants it back, including Haircut Dude.
• Dude 3 is a sheriff. He’s also looking for Dude 2, as part of his investigation into the drug-deal-gone-wrong. He realizes pretty quick that he’s in over his head and probably gonna die.
• Dude 4 is a bounty hunter. He finds Dude 2 and offers to protect him, in exchange for the money.
• Haircut Dude kills Dude 2 & 4 & the drug dealers & several others, but he also randomly spares some people, including Dude 2.

I disagree with the other fella who said there’s no moral or theme. This story is all about destiny, fate and the ever-persistent approach of our own deaths, and also we’re all responsible for our own actions but maybe not our own fates. The story is dripping with metaphor.